Series 20 Model 21


2-Way Normally Open Valve


A complete line of valves with a great selection of options and exceptional proven performance. The standard in the field. Air, water, and other fluids compatible with standard Buna seals. Hot water, steam, gasoline, and many oils require special seal materials.

  • The flagship valve initially created for the fluid power industry.
  • Heavy duty and made of stainless steel.
  • A real workhorse with proven performance.
  • It has the greatest amount of options available of all the valves.
  • Wide range of orifice sizes from 1/32" to 1/8".
Valve specifications — Series 20 Model 21
+ MAX. OPER.
PRESS. DIFF.
ORIFICE SIZECV FACTORVALVE NUMBER
GROMMET HOUSING
CONDUIT HOUSING
ACDC  1/8 NPT PORTS1/4 NPT PORTS1/8 NPT PORTS1/4 NPT PORTS
400(700)*400(700)*1/32.02421G7XGM21G9ZGM21G7XCM21G9ZCM
235(500)235(500)3/64.05321H7XGM21H9ZGM21H7XCM21H9ZCM
150(350)150(350)1/16.09521J7XGM21J9ZGM21J7XCM21J9ZCM
100(150)100(150)3/32.15621K7XGM21K9ZGM21K7XCM21K9ZCM
35(40)35(40)1/8.20121N7XGM ^21N9ZGM ^21N7XCM ^21N9ZCM ^

^ VALVES WITH 1/8 N.O. ORIFICE ARE UL LISTED ONLY
* FKM seals not recommended for pressure ratings above 500 PSI.
+ Ratings in brackets are optional extended ratings; consult factory

Ordering Information:

When ordering valves or repair packs add voltage and frequency to complete valve number. for examples: valve (21J9ZGM 120/60) repair pack (K21JDX AC)

When ordering operators add the letter “O” to the front of the valve number, replace body port number with the letter “D”: example: operator (O21JDDGM 120/60)


Operating Conditions

Media
Air, water, and other fluids compatible with standard Buna seals. Hot water, steam, gasoline, and many oils require special seal materials. (Series 20 pressure ratings may change due to the viscosity of the liquid.)*
Valve Temperature Range
Standard Valves – 0°F (-18°C) to 104°F (40°C) ambient; 0°F (-18°C) to 150°F (65°C) media. Optional Valves – can tolerate much higher or much lower ambient and media temperatures.
Maximum Operating Pressure Differentials
See table above.
Burst Pressure
5000 PSI
Leakage
Bubble tight for standard valves.
Vacuum
To 5 Microns*

Electrical Characteristics

Coil Voltage
12/DC, 24/DC, 48/DC, 125/DC, 120/60-110/50, 240/60, and 24/60.
Nominal Power
AC — 8.7 Watts DC — 9.5 Watts
Coil Construction
Molded (Std.), Non-molded Class A and Potted Class F or Class H (Opt.)
Typical Response Time on Air
4 - 16 Milliseconds
Operating Speed
Up to 600 CPM
Duty Cycle
Continuous

Mechanical Characteristics

Body
Stainless Steel (Std.) or Brass (Opt.)
Internal Components
Stainless Steel. Copper – AC Only.
Elastomers
Nitrile (Buna) (Std.). Many other elastomers available.*
Orifice Diameter
See table above.
Porting
Standard 1/8" and 1/4" NPT (other ports available)*
Housing
Grommet and 1/2" NPT conduit - many options available.*
Listings
Most valves are UL and CSA listed.*
Life Expectancy
Millions of cycles, depending on application, lubrication, etc.
Valve Weight
Grommet Valve: 1.13 lb Conduit Valve: 1.19 lb
Repair Packs
See table above.
Options
Alternate Port Locations, Metering, Manual Override, Alternate Elastomers, Spade Terminal Coil, European Style DIN, Explosion Proof and Magnetic Latching Coil

Series 20 General Purpose Valves Conduit

Technical drawing — MODEL 21 1 4 NPT CONDUIT
MODEL 21 1/4-18 NPT 2WNO CONDUIT CONNECTION
Technical drawing — MODEL 21 1 8 NPT CONDUIT
MODEL 21 1/8-27 NPT 2WNO CONDUIT CONNECTION
Technical drawing — MODEL 21 MANUAL OVERRIDE CONDUIT
MODEL 21 MANUAL OVERRIDE 2WNO CONDUIT COIL CONNECTION
 

Series 20 General Purpose Valves DIN

Technical drawing — MODEL 21 1 4 NPT DIN
MODEL 21 1/4-18 NPT 2WNO DIN STYLE COIL
Technical drawing — MODEL 21 1 8 NPT DIN
MODEL 21 1/8-27 NPT 2WNO DIN STYLE COIL
Technical drawing — MODEL 21 MANUAL OVERRIDE DIN
MODEL 21 MANUAL OVERRIDE 2WNO DIN STYLE COIL
 

Series 20 General Purpose Valves Grommet

Technical drawing — MODEL 21 1 4 NPT GROMMET
MODEL 21 1/4-18 NPT 2WNO GROMMET WITH LEADS
Technical drawing — MODEL 21 1 8 NPT GROMMET
MODEL 21 1/8-27 NPT 2WNO GROMMET WITH LEADS
Technical drawing — MODEL 21 MANUAL OVERRIDE GROMMET
MODEL 21 MANUAL OVERRIDE 2WNO GROMMET HOUSING WITH LEADS
 

Series 20 General Purpose Valves Yoke Leads

Technical drawing — MODEL 21 1 4 NPT YOKE LEADS
MODEL 21 1/4-18 NPT 2WNO MOLDED COIL WITH YOKE
Technical drawing — MODEL 21 1 8 NPT YOKE LEADS
MODEL 21 1/8-27 NPT 2WNO MOLDED COIL WITH YOKE
Technical drawing — MODEL 21 MANUAL OVERRIDE YOKE LEADS
MODEL 21 MANUAL OVERRIDE 2WNO MOLDED COIL WITH LEADS
 

Series 20 General Purpose Valves Yoke Spades

Technical drawing — MODEL 21 1 4 NPT YOKE SPADES
MODEL 21 1/4-18 NPT 2WNO SPADE COIL WITH YOKE
Technical drawing — MODEL 21 1 8 NPT YOKE SPADES
MODEL 21 1/8-27 NPT 2WNO SPADE COIL WITH YOKE
Technical drawing — MODEL 21 MANUAL OVERRIDE YOKE SPADES
MODEL 21 MANUAL OVERRIDE 2WNO YOKE WITH SPADE TERMINALS
 

Series 20 General Purpose Valves Conduit/Bracket Connection

Technical drawing — MODEL 21 CON BRKT 1 4 NPT
MODEL 21 1/4-18 NPT 2WNO CONDUIT/BRACKET CONNECTION
Minimum quantity required. Please contact sales for additional assistance.
sales@peterpaul.com
Technical drawing — MODEL 21 CON BRKT 1 8 NPT
MODEL 21 1/8-27 NPT 2WNO CONDUIT/BRACKET CONNECTION
Minimum quantity required. Please contact sales for additional assistance.
sales@peterpaul.com
Technical drawing — MODEL 21 CON BRKT MANUAL OVERRIDE
MODEL 21 MANUAL OVERRIDE 2WNO CONDUIT/BRACKET CONNECTION
Minimum quantity required. Please contact sales for additional assistance.
sales@peterpaul.com
 

Series 20 General Purpose Valves Grommet/Bracket Connection

Technical drawing — MODEL 21 GROM BRKT 1 4 NPT
MODEL 21 1/4-18 NPT 2WNO GROMMET/BRACKET WITH LEADS
Minimum quantity required. Please contact sales for additional assistance.
sales@peterpaul.com
Technical drawing — MODEL 21 GROM BRKT 1 8 NPT
MODEL 21 1/8-27 NPT 2WNO GROMMET/BRACKET WITH LEADS
Minimum quantity required. Please contact sales for additional assistance.
sales@peterpaul.com
Technical drawing — MODEL 21 GROM BRKT MANUAL OVERRIDE
MODEL 21 MANUAL OVERRIDE 2WNO GROMMET/BRACKET HOUSING WITH LEADS
Minimum quantity required. Please contact sales for additional assistance.
sales@peterpaul.com

Series 20 OPERATORS CONDUIT

Technical drawing — OPER S20 21 125 NPT COND
MODEL 21 1/8-27 NPT 2WNO CONDUIT CONNECTION
Technical drawing — OPER S20 21 250 NPT COND
MODEL 21 1/4-18 NPT 2WNO CONDUIT CONNECTION
 

Series 20 OPERATORS DIN

Technical drawing — OPER S20 21 125 NPT DIN
MODEL 21 1/8-27 NPT 2WNO DIN STYLE COIL
Technical drawing — OPER S20 21 250 NPT DIN
MODEL 21 1/4-18 NPT 2WNO DIN STYLE COIL
 

Series 20 OPERATORS EXPLOSION PROOF

Technical drawing — OPER S20 21 125 NPT EP
MODEL 21 1/8-27 NPT 2WNO EXPLOSION PROOF
Technical drawing — OPER S20 21 250 NPT EP
MODEL 21 1/4-18 NPT 2WNO EXPLOSION PROOF
 

Series 20 OPERATORS GROMMET

Technical drawing — OPER S20 21 125 NPT GROM
MODEL 21 1/8-27 NPT 2WNO GROMMET WITH LEADS
Technical drawing — OPER S20 21 250 NPT GROM
MODEL 21 1/4-18 NPT 2WNO GROMMET WITH LEADS
 

Series 20 OPERATORS YOKE LEADS

Technical drawing — OPER S20 21 125 NPT YOKE LEADS
MODEL 21 1/8-27 NPT 2WNO MOLDED COIL WITH YOKE
Technical drawing — OPER S20 21 250 NPT YOKE LEADS
MODEL 21 1/4-18 NPT 2WNO MOLDED COIL WITH YOKE
 

Series 20 OPERATORS YOKE SPADE

Technical drawing — OPER S20 21 125 NPT YOKE SPADE
MODEL 21 1/8-27 NPT 2WNO SPADE COIL WITH YOKE
Technical drawing — OPER S20 21 250 NPT YOKE SPADE
MODEL 21 1/4-18 NPT 2WNO SPADE COIL WITH YOKE
 
 
Nomenclature, all valve series except 58

Cv Flow Formulae

PeterPaul has created this page for you so you can calculate the flow or Cv (flow coefficient) to make the relationship visible between the pressure drop (the difference in pressure between two points of a liquid/gas carrying network) and the flow rate.

The use of this flow coefficient (Cv) calculator offers a standard calculation to compare valve capacities and sizing for a wide range of applications. The type and sizing of a valve or regulator can have a large impact on the performance of the assembly for transferring gas or liquids in the system.

Our sales department is ready to answer questions and to solve your valve needs. Please feel free to call, chat or email us.

Liquid Flow

Calculate Flow in GPM
PSI
GPM
Calculate Cv
GPM
PSI
Calculate P1−P2
GPM
PSI

Gas Flow P2 > 53% of P1 (subsonic)

Calculate Flow in CFM
PSIA
PSIA
°R
CFM
Calculate Cv
CFM
PSIA
PSIA
°R
Calculate P1 (approx.)
CFM
PSIA
°R
PSIA
Calculate P2 (approx.)
CFM
PSIA
°R
PSIA

Gas Flow P2 < 53% of P1 (sonic)

Calculate Flow in CFM
PSIA
°R
CFM
Calculate Cv
CFM
PSIA
°R
Calculate P1
CFM
°R
PSIA

DISCLAIMER: Gas flow is only an approximation using Cv.